Pump



M'ay 27, 1969 H. c. AMos ET Ax. 3,446,149

PUMP Filed Feb. 2, i967 May 27, 1969 H C, ANOS ET AL 3,446,149

PUMP

Filed Feb. 2, 1967 dazi/220%@ ZZ Z5 INVENTORS. 0 Ha/ff c: ,4/1405 United States Patent O 3,446,149 PUMP Homer C. Amos, 1086 Marshal Way, and Edward T. Strickland, 4700 E. Sunny Dunes Road, both of Palm Springs, Calif. 92262 Filed Feb. 2, 1967, Ser. No. 613,562 Int. Cl. F04b 19/16; F04d 5/00 U.S. Cl. 103-84 16 Claims ABSTRACT OF THE DISCLOSURE Cross reference to related application The pump of this invention may be used for pumping and debubbling molten glass in practicing the invention described in our copending patent application Serial No. 556,800, entitled Apparatus and Process for Extruding Fibers, filed May 13, 1966, the disclosure of which is incotporated herein by reference.

Summary and background of invention The present invention relates to a pump for pumping uids, and particularly viscous liquids, and requires only one moving element. One element of the pump has a discontinuous surface to provide a plurality of cooperating spaces or chambers, and the other element has a relatively smooth and continuous surface spaced from and cooperating with the discontinuous surface of the first element. The liquid moves through the pump between said surfaces, and the viscosity of the liquid is utilized in effecting the pumping action. The pump further has the property of rejecting bubbles in the liquid, and is useful in efficient-ly mixing, milling or homogenizing liquids, or liquid mixtures. Typical prior art pumps include a number of operative elements which are subject to wear, and also which give rise to cavitation and viscous drag as a result of the valving and porting employed.

Accordingly, it is an object of the present invention to provide a new `and useful pump.

It is an additional object of this invention to provide a pump type device for effecting the transfer of a liquid from an inlet to an outlet thereof while rejecting bubbles in the liquid.

It is a further object of this invention to provide a pump which is particularly useful for handling highly viscous fluids.

Another object of this invention is to provide a pump type device for efficiently mixing, milling, or homogenizing liquids or liquid mixtures.

A still further object of this invention is to provide a pump which is characterized by relatively little wear of the elements thereof.

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Brief description of drawings These and other objects, features and advantages of the present invention will be better understood from a consideration of the following description taken in conjunction with the drawings in which:

FIGURE 1 is a diagrammatic cross-sectional view of a pair of relatively movable elements illustrating the principles of the present invention;

FIGURES 2a and 2b are graphs illustrating pumping properties of a pump according to the present invention;

FIGURE 3 is a perspective view of a pump employing the concepts of the present invention;

FIGURE 4 is an elevational view, partially in section, of the pump shown in FIGURE 3;

FIGURE 5 is a plan view, partially in section, of the pump shown in FIGURES 3 and 4;

FIGURE 6 is a cross-sectional view taken along a line 6-6 of FIGURE 5;

FIGURE 7 is a partial perspective view of a modification of the pump shown in FIGURE 3;

FIGURE 8 is a diagram illustrating exemplary dimensions of a discontinuous element of a pump according to the invention;

FIGURE 9 is a cross-sectional view of another form of pump employing the concepts of the present invention;

FIGURE 10 is a bottom view of the discontinuous element of the pump shown in FIGURE 9;

FIGURE 11 is a cross-sectional view taken along a line 11-11 of FIGURE 9; and

FIGURE l2 is a fragmentary perspective view of an element of another form of pump employing the concepts of the present invention.

Description of preferred embodiments Referring now to the drawings, FIGURE 1 diagrammatically illustrates in cross section a discontinuous configured element 10 disposed above and adjacent to a relatively smooth and `continuous element 11. The two elements are relatively movable, and for purposes of illustration it is assumed that the element 10 is stationary and the element 11 is moved steadily and continuously to the left as indicated by an arrow 12. An inlet passage 13 communicates with a supply of liquid to be pumped or to be debubbled, mixed, milled or homogenized. The liquid in the passage 13 is dragged along by the moving surface 14 of the element 11 in the direction of the arrow 12. The liquid th-us is dragged through a restricted space or chamber 15 into enclosure or chamber 16 toward an outlet passage 17.

Assuming that there is no back pressure at the outlet passage 17, the speeds of various laminae or portions of the liquid in the chamber 15 vary from a maximum of the speed of the surface 14 where the liquid is in contact with this surface, down to zero where the liquid is in contact with the upper surface or boundary 18 of the chamber 15. The average speed of the liquid in the chamber 15 is one-half the speed of the surface 14, and the rate of ow through the chamber 15 may be calculated by multiplying one-half the speed of the surface 14 times the cross-sectional area of the chamber 15. A similar calculation can be made to determine the rate of flow of the liquid through a second restricted space or chamber 3 20. Since more liquid flows into the chamber 16 through the chamber 15 than can exit through the more restricted chamber 20, the excess flows through the outlet passage 17.

Assuming now that the outlet passage 17 is closed, the excess liquid flows backwards through the chamber 15 resulting in a pressure at the outlet passage 17. As an example, if the chamber 15 is .006 inch high and lz inch wide (right to left as viewed in FIGURE 1), the chamber 20 is .001 inch high and 1/16 inch Wide, the viscosity of the liquid is 300 poises, and the speed of the surface 14 is inches per second, then the pressure produced at the outlet passage 17 will be approximately 600 p.s.i. If the outlet passage 17 is partially restricted, the output and pressure vary continuously and linearly from maximum flow at zero back pressure to zero flow at maximum back pressure. This relationship is indicated by a line 22 in the graph of FIGURE 2a.

In providing a pressure pump according to the teachings of the present invention, the best impedance match and therefore the highest etiiciency is obtained if the pump has a maximum output pressure, at zero flow, of twice the desired output pressure. The desired pressure, and thus the point of maximum eiciency as a pressure pump, is indicated at a midpoint 23 on the line 22 in FIGURE 2a. Since both pressure at a xed flow rate and ow rate at a xed back pressure are linear with respect to the relative speed between the two elements, the graph of FIGURE 2b may be used to indicate either volume of flow or pressure with respect to speed.

When utilizing the concepts of the present invention v for debubbling, some back pressure is required even though no output pressure may be needed in a given debubbling application. If it is desired to mix, mill or homogenize, the violent shear occurring in chamber accomplishes this action, and an artificial back pressure is not necessary.

The pumping concepts of the present invention may be embodied in various practical forms, such as, cylindrical, disk-shaped, spherical, or conical. A cylindrical embodiment is illustrated in FIGURES 3 through 6 and includes an inner discontinuous configured element 30 and an outer cylindrical element 31. The cylindrical element 31 is positioned on the element 30 as shown in FIGURE 4, and preferably the element 31 is rotated at the desired speed while the element 30 is maintained stationary. These two elements, which form a pump employing the concepts of the present invention, are positioned within the liquid to be pumped, debubbled, mixed, and so forth. The element 31 has a smooth inner cylindrical surface 32. A plurality of ribs are provided at the top of the element 31 and are coupled with a connector 34 which in turn is coupled with a shaft 35 for rotating the element 31. Preferably, a flexible shaft is provided to alleviate alignment problems between the elements.

The configurated element 30 may be machined from a. solid cylinder, and includes a plurality of inlet passages 40 corresponding to the passage 13 in FIGURE l. Radially extending pumping arms or members 41 are delined by adjacent passages 40 and are liuted to provide chambers 42 between the elements 30 and 31 corresponding to chamber 16 in FIGURE 1, Leading edge surfaces 43 dene chambers 44 corresponding to the chamber 15 in FIGURE 1, while trailing edge surfaces 45 define chambers 46 corresponding to the chamber 20 in FIGURE 1. The configuration of the surfaces and chambers may be better in FIGURE 8. The surfaces 45 may be beveled at 47 to form a wedge bearing. A plurality of radial holes 48 provide outlet feeder tubes communicating between the chambers 42 and a central outlet bore 49 (note FIGURES 5 and 6), and thus the holes and bore serve as outlet passages corresponding to the outlet passage 17 in FIGURE 1. The lower end of the element 30 is machined at 50 to provide an inlet area for the pump. The circumferential edges 51 and 52 at the top and bottom, respectively, of the element 30 essentially provide bearing surfaces and seals at the top and bottom of the inner surface 32 of the element 31.

The configured element 30 is secured to the bottom 54 of a container, within which the liquid to be pumped, debubbled, etc. is disposed, by means of a plurality of bolts 55. The bore 49 in the congured element 30 communicates with a bore 56 (note FIGURE 6) in the base 54, and a suitable tube or the like (not shown) may be coupled therewith for conveying the liquid expelled from the pump.

When the pump is placed within a container of liquid, the liquid flows into the inlet passages 40 from the inlet area at the lower end of the element 30 and tends to How upwardly through the passages 40 because of bubbles in the liquid. Upon rotation of .a cylindrical element 31, the liquid moves from the passages 40, through respective chambers 44, into respective chambers 42, through respective outlet passages 48, and exits through the bores 49 and 56.

This particular pump construction, e.g. cylindrical, is especially adapted to continuously remove bubbles from the liquid. Bubbles, unless very tiny, in the liquid do not pass through the chambers 44 because such bubbles tend to remain in, or return to, the low pressure area in the inlet passages 40. The rotation of the cylindrical element 31 causes rapid rotation of the liquid in the inlet passages 40, and the resulting centrifugal force causes the bubbles rejected by the pumping members 41 to coalesce into large bubbles at the center of the passages 40. The large bubbles then rise out of the pump to the surface of the liquid. In some applications, particularly with highly viscous liquids, it may be desirable to increase the axial flow into the chamber 40, and this may be accomplished by aixing vanes 60 at the upper end of the cylindrical element 31 as shown in FIGURE 7.

The various dimensions of a pump can be selected to provide the desired output volume and pressure. For example, a one inch diameter (internal diameter of surface 32) cylindrical pump of the nature of that described above having 'an active length of 'one inch iand a speed of 190 r.p.m. can be constructed to have an output volume of approximately nine cubic inches per minute at no back pressure, an output pressure `of about 900 p.s.i. at zero output, and has a maximum efficiency of 4.5 cubic inches per minute at approximately 450 p.s.i. These points are illustrated respectively at 62, 63 and 23 in FIGURE 2a. The output volume can be computed based on the noback-pressure output being equal to the efficiency (E) times the swept volume per minute (VS). Vs is equal to L(t1-t2)Nv, :where E is equal to the efficiency ('1/2) or average speed of the liquid, L is equal to the active length of the surface 43 (one inch), t1 is equal to the spacing of the surface 43 (.006 inch) from the interior surface 32, t2 is equal to the spacing of the surface 45 (.001 inch), N is equal to the number (six) of the flutes or spaces 42, and v is equal to the linear velocity in inches per minute (ten times sixty). By substituting in the values it will b-e found that the no-back-pressure output is nine cubic inches per minute. The surface 45 may be one thirty-second inch wide and have a one thirty-second inch wide twenty degree bevel at 47 to provide a wedge bearing, The pressure (P) at no output volume is equal to nvw/gtz, where q is the viscosity in poises (450), v is the linear velocity in centimeters per second (25.4), w is the length of the liquid path (width of surface 43, or one-eighth inch) in centimeters (.3175), g is equal to gravity (980), and tis one half the spacing of the surface 43 in centimeters (.SX .006 2.54). Substituting in the values it will be seen that the output pressure is 'above 900 p.s.i. at no volume output. As another example, a two inch diameter pump having an active length of two inches and having dirnensions as shown in FIGURE 8 (the radius R equals one inch), and assuming the same speed and same viscosity of the liquid as stated above, will provide an output volume of approximately seventy-two cubic inches per minute at no back pressure and an output pressure of approximately 39 p.s.i. at zero output volume.

The pump concepts described herein can be employed for pumping liquids over any range of viscosity, but they are especially useful with highly viscous liquids which present numerous problems, such as cavitation, when pumped by conventional pumps. Not only is a pump constructed in accordance with the teachings of the present invention particularly resistant to cavitation and loiw in viscous drag resulting from the valving and porting o-f many conventional pumps, but also the present pump ladvantageously employs the viscous nature of the liquid in the pumping of the liquid.

Frequently, in various industries in which viscous or foaming liquids are used, the elimination of bubbles presents a serious problem. Since a pump according to the priesent invention is characterized by the remarkable property of rejecting and refusing to pump bubbles, 1t 1s particularly useful in such industries since the l1qu1d can be debubbled merely by running it through the pump. The pump of the present invention thus is particularly use- -ful in the glass industry where small bubbles, known as seeds, are the cause of a substantial amount of rejected product and set sharp limits to the output of a glass furnace or tank. When used in molten glass, for example, the elements of the pump are formed of high temperature resistant material, such as molybdenum or platinum.

An additional virtue of the present pump is the homogenizing, mixing or milling effect provided on the liquid pumped therethrough. The present pump is useful in widely varying industries in eliminating strlae and cords from glass, in rapidly and effectively milling paint plgments into vehicles, and quickly rendering vinyl plastisols completely homogeneous. As an example, a cylindrical pump of the nature illustrated in FIGURE 3, with the element 30 having a diameter of eleven inches and being ten inches long, and the element 31 being rotated at one hundred revolutions per minute, will deliver approximately one hundred tons per day of debubbled and cordfree glass at a pressure of approximately one hundred pounds per square inch. Of particular signiiicance 1s the simplicity of pumps yaccording to this invention inasmuch as only one moving part is required. Since there are no opening and closing valves or sliding port mechamsms or other metal surfaces intermittently sliding upon each other, wear is virtually nonexistent.

An embodiment of a pump constructed in accordance With the teachings of the present invention having spherical surfaces is illustrated in FIGURES 9 through l1. In this embodiment, a rotatable configured element 70 is positioned Within a spherical recess 71 in a stationary element 72. Inasmuch as the contact surfaces are spherical, this arrangement is self-aligning. FIGURE 10 is a bottom View of the configured element 70 and illustrates a plurality of notches 73 which define inlet passages corresponding to the chamber 13 in FIGURE 1. The pumping arms or members 74 between the passages 73 are iiuted at 75 to provide chambers corresponding to the chamber 16 in FIGURE l. The leading surfaces 76 define the chambers corresponding to the chamber E in FIGURE l, and the trailing surfaces 77, which also extend to the periphery as indicated at 78 of each member 74, define chambers :corresponding to the chamber 20 in FIGURE 1. The leading edges 77a of the trailing surfaces 77 are beveled or rounded to form a wedge bearing. The center 79 of the element 70 provides an outlet passage. The outlet passage 79 communicates between the chambers 75, and a bore 80 and outlet tube 81 in the element 72.

As will be apparent from the preceding discussion, if the coniigured element 70 is rotated in the direction shown by the arrow 82, liquid entering the inlet passages 73 will be pumped out through the outlet passage 79. In this ernbodiment, an additional variable is encountered inasmuch as the spacing between the facing surfaces of the elements 70 and 72 is not iixed and is essentially provided by the uid being pumped. If the back pressure at the outlet 79 becomes suiiiciently large, the fluid causes the configured element 70 to rise thereby diminishing the pumping action. Thus, the downward pressure on the driving shaft 83 is maintained higher than the back pressure to ensure proper pumping action and, also, the output pressure can be controlled as a function of the shaft pressure.

A fragmentary perspective view of a disk-shaped configured element 85 is illustrated in FIGURE 12. In this bottom view of the portion of the disk, which may have a number of pumping arms or members 86 such as eight, the peripheral edge is open thereby providing an inlet for the liquid into an inlet passa-ge 87 which corresponds to the chamber 13 in FIGURE 1. A groove or slot 88 provides a chamber corresponding to the chamber 1-6 in FIGURE l. A leading surface area 89 provides a chamber corresponding to the chamber 15 in FIGURE l, and a trailing Isurface area 90 which extends to the periphery at 91 of the member 86 defines a chamber corresponding to the chamber 20 in FIGURE 1. The slots 88 communicate with a central bore 92 which is closed at the top of the disk. The bore 92 provides an outlet passage which communicates with a corresponding bore in an underlying flat and smooth element (not shown) corresponding to the element 72 in FIGURE 9. This embodiment i-s like the spherical embodiment except the facing surfaces are planar rather than curved, and thus the smooth element is merely a flat disk with the coniigured element disposed thereon.

In each of the pump embodiments disclosed herein, either one of the two elements may be the movable element. The intake passages (15, 40, 73 and 187) generally are made as large and open as possible at the expense of the outlet passages. This is done to reduce the possibility of cavitation if the pump is operated at a fast speed since there is a small, or substantially zero, fluid head at the intake of the pump. The pumps are reversible and can be so used if desired, but a cavitation problem may be encountered at the small intake unless the pump is run slowly. However, the .specific design of a pump for a particular application usually will be for its use in only one direction. Inasmuch as -gases and liquids both are uids having viscosity, gases also can be pumped by a pump employing the concepts of the present invention.

The present embodiments of this invention are to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description or abstract of the disclosure, and all changes which come within the meaning and range of equivalency of the claims therefore are intended to be embraced therein.

What is claimed is:

1. A pump for pumping tiuid comprising iirst and second relatively rotatable element means,

the iirst of said element means having a relatively smooth continuous surface,

the second of said element means having a configured surface, said configured surface comprising a plurality of radially extending pumping members disposed adjacent the surface of said iirst element means and having fluid inlet chambers therebetween for receiving a fluid to be pumped, each of said pumping members comprising (a) an elongated leading surface disposed substantially parallel to the surface of said iirst element means and spaced therefrom a iirst predetermined distance, said leading surface having a relatively sharp leading edge and having a length substantially greater than the width thereof, the Width of said leading surface being the dimension thereof in the direction of relative rotation between said first and second element means, (b) an elongated trailing surface spaced a second predetermined distance from the surface of said first element means, said first predetermined distance being greater than said -second predetermined distance, said trailing surface having a width less than said width of said leading surface, and Y (c) said leading and trailing surfaces defining an outlet chamber therebetween through which said fluid is pumped, and

said second element means including a fiuid outlet interconnected with said outlet chambers.

2. A pump for pumping fiuid comprising first and second relatively rotatable element means,

the first of said element means being cylindrical and having a relatively smooth continuous inner surface,

the second of said element means being generally cylindrical in shape and having a configured peripheral surface, said configured surface comprising a plurality of radially extending pumping members disposed adjacent said surface of said first element means and having fluid inlet chambers therebetween for receiving a fluid to be pumped, each of said pumping members comprising (a) an elongated leading surface disposed substantially parallel to the surface of said first element means and spaced therefrom a first predetermined distance, said leading surface having a relatively sharp leading edge and having a length substantially greater than the width thereof, the width of said leading surface being the dimension thereof in the direction of relative rotation between said first and second element means,

(b) an elongated trailing surface spaced a second predetermined distance from the surface of said first element means, said first predetermined distance being greater than said second predetermined distance, said trailing surface having a width less than said width of said leading surface, and

(c) said leading and trailing surfaces defining an outlet chamber therebetween through which said fluid is pumped, and

said seconod element `means including a plurality of outlet passageways communicating with said respective outlet chambers and with a central bore therein for providing an outlet for said pump.

3. A- pump as in claim 2 wherein said second element means has upper and lower circumferential edges providing bearing surfaces and seals with said surface of said first element means respectively near the top and bottom thereof, the radius of said circumferential edges being approximately the same as the radius of said trailing surface.

4. A pump for pumping fiuidcomprising first and second relatively rotatable element means,

the first of said element means having a relatively smooth spherical shaped surface and a central opening therethrough,

the second of said element means having a generally spherical shaped surface for mating with the spherical shaped surface of said first element means, said surface of said second element being configured and comprising a plurality of radially extending pumping .members disposed adjacent said surface of said first element means and having fluid inlet chambers therebetween for receiving a fiuid to -be pumped, each of said pumping members comprising (a) an elongated leading surface disposed substantially parallel to the surface of said first element means and spaced therefrom a first predetermined distance, said leading surface having a relatively sharp leading edge and having a length substantially greater than the width thereof, the width of said leading surface being the dimension thereof in the direction of relative rotation 'between said first and second element means,

(b) an elongated trailing surface spaced a second predetermined distance from the surface of said first element means, said first predetermined distance being greater than said second predetermined distance, said trailing surface having a width less than said width of said leading surface, and

(c) said leading and trailing surfaces defining an outlet chamber therebetween through which said fiuid is pumped,and

said second element means including a fluid outlet interconnected with said outlet chambers and with said central opening through said first element means.

5. A pump as in claim 4 wherein said fiuid outlet of said second element means is a central opening therein communicating with said central opening through said first element means, and said second element means is disposed above said first element means.

6. A pump for pumping fluid comprising first and second relatively rotatable element means,

the first of said element means having a relatively smooth fiat surface and an opening therethrough,

the second of said element means being generally discshaped and having a configured surface, said configured surface comprising a plurality of radially extending pumping members disposed adjacent said surface of said first element means and having fluid inlet chambers therebetween for receiving a fiuid to be pumped, each of said pumping members comprismg (a) an elongated leading surface disposed substantially parallel to the surface of said first element means and spaced therefrom a first predetermined distance, said leading surface having a relatively sharp leading edge and having a length substantially greater than the width thereof, the width of said leading surface being the dimension thereof in the direction of relative rotation between said first and second element means,

(b) an elongated trailing surface spaced a second predetermined distance from the surface of said -first element means, said first predetermined distance being greater than said second predetermined distance, said trailing surface having a width less than said width of said leading surface, and

(c) said leading and trailing surfaces defining an outlet chamber therebetween through which said fluid is pumped, and

said second element means including a fluid outlet interconnected with said outlet chambers and with said opening through said first element means.

7. A pump as in claim 6 wherein said fiuid outlet of said second element means is a central opening therein communicating with said central opening through said first element means, and said second element means is disposed above said first element means.

l8. A pump having first and second relatively movable elements for immersion in a fiuid for pumping said fiuid comprising a first rotatable element having a relatively smooth cylindrical inner surface,

a second stationary element mounted in said first element and having a configured outer surface,

said configured outer surface comprising a plurality of radially extending pumping members disposed adjacent said inner surface of said first element and grooves between said pumping members forming fiuid inlet chambers for receiving a fluid to be pumped, each of said pumping members comprising (a) an elongated leading surface disposed substantially parallel to said inner surface of said first element and spaced therefrom a first predetermined distance, said leading surface having a relatively sharp leading edge and having a length several times or greater than the width thereof, the width of said leading surface being the dimension thereof in the direction of rotation of said first element,

(b) an elongated trailing surface spaced a second predetermined distance from said inner surface of said first element, said first predetermined distance being greater than said second predetermined distance, said trailing surface hava width less than said width of said leading surface, and

(c) a groove between said leading and trailing surfaces defining an outlet chamber therebetween for each of said pumping members, and a plurality of passageways communicating with said outlet chamber, and

said second element means -including a central bore therein providing a fluid outlet communicating with said passageways of each of said pumping members for interconnecting the respective outlet chambers thereof with said bore.

9. A pump as in claim A8 wherein said lsecond stationary element including upper and lower circumferential edges providing bearing surfaces and seals respectively near the upper and lower ends of said first element.

10. A pump as in claim 8 wherein said first element including a plurality of vanes afiixed at the upper end thereof to increase the axial flow of fluid into said inlet chambers of said second elemen-t.

11. A pump for pumping molten glass comprising first and second relatively rotatable elements formed of high temperature resistant material,

the first of said elements having a relatively smooth continuous surface,

the second of said elements having a configured surface, said configured surface comprising a plurality of radially extending pumping members disposed adjacent the surface of said first element and having fluid inlet chambers therebetween for receiving said molten glass, each of said pumping members comprising (a) an elongated leading surf-ace disposed substantially parallel to the surface of said first element and spaced therefrom a first predetermined distance, said leading lsurface having |a relatively sharp leading edge and having a length several times or greater than the width thereof. the Width of said leading surface being the dimension thereof in `the direction of relative motion between said first and second elements,

(b) an elongated trailing surface disposed substantially parallel to the surface of first element and spaced a second predetermined distance therefrom, said first predetermined distance being greater than said second predetermined distance, said trailing surface having a width less than said width of said leading surface, and

(c) said leading and trailing surfaces defining an outlet chamber therebetween through which said glass is pumped, and

said second element including a fluid outlet interconnected with said outlet chambers.

12. A glass pump as in claim 11 wherein said first element is cylindrical and has a wall which is relatively thin with respect yto the radius thereof, and

said second element is mounted in `said first element.

13. A glass pump asin claim 11 wherein Isaid relatively smooth continuous surface is a concave spherical shaped surface,

said configured surface is generally convex and mounted upon said spherical surface of said first element, and

said first element including a central fluid outlet communicating with the fluid outlet of said second element.

14. A glass pump as in claim v11 wherein said relatively smooth continuous surface is planar,

said first element is generally disc-shaped and mounted upon said surface of said first element, and

said `first element including a central uid outlet communicating with the fluid outlet of said second element.

15. A pump for pumping molten glass comprising first and second relatively rotatable elements,

the first of said elements being relatively thin compared with said second element and having a relatively smooth and continuous inner surface,

the second of said elements having a configured outer surface, said configured surface comprising la plurality of radially extending pumping members disposed adjacent said surface of said first element and having molten glass inlets therebetween for receiving 4molten glass to be pumped, each of said pumping members comprising (a) Ian elongated leading surface disposed substantially parallel to said surface of said first element and spaced therefrom a first predetermined distance. said leading surface having a length substantially greater than the width thereof, lthe Width thereof being the dimension in the direction of rotation between said first and second elements,

(b) an elongated trailing surface spaced a second predetermined distance from said surface of said first element, said first predetermined distance being greater than said second predetermined distance, said trailing surface having a width less than said width of said leading surface, and

(c) said leading and trailing surfaces defining an outlet chamber therebetween through which said molten glass is pumped, and

said second element including a fluid outlet interconnected with said outlet chamber.

16. Debubbling apparatus comprising first and second relatively rotatable elements,

the first of said elements having a relatively smooth continuous surface,

the second of said elements having a configured `surface, said configured surface comprising a plurality of outwardly extending pumping members disposed adjacent said surface of said rst element and having fluid inlet chambers therebetween for receiving Ia fluid to be debubbled, each of said pumping members comprising (a) an elongated leading surface disposed lsubstantially parallel to said surface of said rst element and spaced therefrom a first predetermined distance, said leading surface having a sharp leading edge and having a length substantially greater than the width thereof, the Width of said leading surface being the dimension thereof `in the direction of relative rotation between said first and second elements,

(b) an elongated trailing surface spaced a second predetermined distance from said surface of said first element, said first predetermined distance being greater than said second predetermined distance, said trailing surface having a width less than lsaid width 4of said leading surface, and

1 1 1 2 l(c) said leading and trailing surfaces dening an y3,123,861 3/ 1964 Westover 10S-'84 outlet chamber `therebeween through which the 3,357,361 12/ 1967 Scott i10S-84 fluid to be debubbled is passed, and 2,718,989 9/ 1955 Day et al. 103-84 said second element including a uid outlet intercon- FOREIGN PATENTS nected with vsaid outlet chambers. 5

363,652. 12/'1958 Switzerland.

References Cited HENRY F. RADUAZO, Primary Examiner. UNITED STATES PATENTS ,41,377,914 `5/1921 Newbigin 10s-s3 U-S-CLX-R- 1,448,079 3/1923 Noeggerarh 103-s4 10 103-95 

